Users with very large music libraries (over 100K) can encounter an issue on updating their library in Clementine for example, possible output in that case:

inotify_add_watch("/run/media/frost/MUSIC_old/Music/[Wheatus]") failed: "No space left on device"

To accommodate the inotify kernel settings for such situations, add a file:

kdesu kate   /etc/sysctl.d/20-inotify.conf

and add fs.inotify.max_user_watches = 1048576 as the content of that file.